1. Field of the Invention
The present invention relates generally to lighting fixtures, and particularly to a fluorescent light fixture activated by an attached detector switch. More particularly, the invention relates to a fluorescent light fixture with a motion detector switch, troubleshooting capabilities, and a quick plug release mechanism for facilitating maintenance. This invention is predominantly directed to fluorescent lighting fixtures that may be utilized in confined spaces, such as a home closet space, and ultimately maintained by nontechnical consumers.
2. Description of Related Art
There is a considerable amount of energy wasted in residential applications by simply leaving the lights on when not needed. Typically the smaller confined spaces, closets, halls, attics, and the like, are generally more prone to being left on after the occupant has left the area. There are few automated controls available for the consumer to control the lighting in these areas. For example, manual switching designs for closet lighting are employed throughout the housing industry. The least expensive is the pull-chain switch. Another method is the standard wall switch that requires additional wiring to be run from the switch to the light. The third and most involved method involves a door switch. This involves carving a switch within the door jam and running a wire back to the light fixture. All three of these installations have disadvantages including leaving the closet light on for an extended period of time if not manually switched off. Recent advances in infrared, photocell, frequency, and timing technologies, however, have made the application of motion detectors, photo sensors, frequency sensors, and timing sensors feasible for commercial use. The National Electric Code, Article 410, requires a lighting fixture installed in a standard two foot deep closet space be of the fluorescent type. Installing and maintaining light fixtures with more complex electronics and sensor systems requires a level of knowledge in electronics typically not enjoyed by the nontechnical consumer. Thus, a need has developed for employing motion and photo sensors on fluorescent light fixtures capable of troubleshooting and easy maintenance by nontechnical residential consumers.
Basic motion sensor operated lighting systems are well known in the prior art. Controls for fluorescent lamps have been devised, and are now commercially available, that will turn a light circuit ON and OFF depending upon the signals provided by occupancy or light sensors. These sensors help to conserve energy and extend the life of the lamp by turning off the lamp when there is sufficient ambient light and/or there is no one occupying the sensing area. Typically, motion detectors are employed to conserve energy by turning off the light fixture when no motion is detected in the sensing region. Other sensors, such as photocells or photo sensors and the like, may be separately or jointly employed in similar applications. Generally, the motion detectors are passive infrared or Doppler technology devices that provide a signal when "occupancy" is detected in the sensing area. In contrast, a photo sensor senses the ambient light to determine if sufficient natural light is available.
The motion detector commonly keeps the light on for a pre-set period of time after motion has been detected. Thus, for example, when a person enters a room that is being sensed by a motion detector integrated with a light fixture, the light comes on for a predetermined period of time and remains on until a set time after motion has no longer been detected.
With increasing commercial availability of lighting fixtures integrated with motion and photo sensors, it has become increasingly more likely that non-trained users will be required to service and maintain these units. Thus, there remains a need for light fixtures integrated with such sensors to have "smart" built-in testing capabilities to accommodate the nontechnical consumer, and provide for minimal maintenance operations at the component level to facilitate part replacement if necessary.
Another problem with these fixture designs is that an infrared motion sensor must be offset from the lamps in order to avoid heat build-up from the lamps which will cause the sensor to activate and possibly fail prematurely. Solutions to this problem have included extending the infrared sensor a distance away from the lamp.
U.S. Pat. No. 5,649,761 issued to Sandell et al., on Jul. 22, 1997, entitled "EMOTION DETECTOR WITH SIDE-PIVOTING LIGHT FIXTURE", teaches a passive infrared motion detector attached to a base containing one or more lamp holders. The motion detector is situated away from the lamps by an arm that is pivotally connected to the back end of the lamp holder. This helps to eliminate the false activations by the thermal energy emitted from the lamps that have just been extinguished. However, the fixture provides no failure mode information for the user, nor does the integral nature of the fixture-sensor assembly allow itself for easy dismantling after a failure is detected.
Another common issue in lighting fixture designs involves integrating the sensor with different fixture housings that do not accommodate the optical viewing angles required by the sensor. Solutions to this problem include integrating the sensor housing within the lamp fixture such that the sensor's field of view always remains undisturbed by the fixture housing.
In U.S. Pat. No. 5,434,764 issued to Lee, et al., on Jul. 18, 1995, entitled, "LIGHTING FIXTURE WITH INTEGRAL MOTION DETECTOR", a one-piece lighting fixture is taught that includes a motion detector internal to the lamp housing. This fixture is predominately used in residential outside lighting, where the decorative style lamp fixture can block the motion detector's field of view. By placing the motion sensor's view port on the front of the lamp fixture housing, the lamp fixture decorative design will not interfere with the sensor's operational viewing area. However, having a "built-in" motion detector complicates any maintenance activity on either of the principle components of fixture.
Other designs have addressed energy management control circuitry to control the light intensity of fluorescent lamps. However, these designs remain electronically complex and lend themselves to factory troubleshooting and repair. For example, in U.S. Pat. No. 5,668,446 issued to Baker on Sep. 16, 1997, entitled, "ENERGY MANAGEMENT CONTROL SYSTEM FOR FLUORESCENT LIGHTING", a light control system is taught that controls the light level for the task being performed in the sensing area. This system adjusts the lamp's intensity in concert with the measured ambient light to reduce the amount of artificial light required. However, the complexity of this design generally prohibits built-in testing capabilities and simple maintenance operations for nontechnical users.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide a lamp fixture and control device for residential applications to minimize energy consumption and therefore minimize the cost of energy required to operate a dwelling.
It is another object of the present invention to provide a lamp fixture and control device for residential applications that increases the life of fluorescent lamps operated under its control.
A further object of the invention is to provide a lamp fixture and control device having built-in testing capabilities for facilitating repair by nontechnical users.
It is yet another object of the present invention to provide a lamp fixture and control device having easily detachable components for simplifying maintenance by nontechnical consumers.
Still other advantages of the invention will in part be obvious and will in part be apparent from the specification.